Method to prepare virtual assay using time of flight mass spectroscopy

ABSTRACT

Systems and methods are disclosed for providing virtual assays of an oil sample such as crude oil based on time of flight mass spectroscopy (TOF-MS) carried out on the oil sample, and the density of the oil sample. The virtual assay provides a full range of information about fractions of the oil sample including naphtha, gas oil, vacuum gas oil, vacuum residue, and other information about the properties of the oil sample. Using the system and method herein, the virtual assay data pertaining to these several fractions of the oil sample and the oil sample itself are obtained without fractionation of the oil sample into the several components.

RELATED APPLICATIONS

Not applicable.

BACKGROUND Field of the Invention

The present invention relates to methods and systems for evaluating anoil sample such as crude oil to provide a virtual assay.

Description of Related Art

Crude oil originates from the decomposition and transformation ofaquatic, mainly marine, living organisms and/or land plants that becameburied under successive layers of mud and silt some 15-500 million yearsago. They are essentially very complex mixtures of many thousands ofdifferent hydrocarbons. In addition to crude oils varying from onegeographical region to another and from field to field, it has also beenobserved that the properties of the crude oil from one field may changewith time, as oil is withdrawn from different levels or areas of thefield. Depending on the source and/or time of withdrawal, the oilpredominantly contains various proportions of straight andbranched-chain paraffins, cycloparaffins, and naphthenic, aromatic, andpolynuclear aromatic hydrocarbons. These hydrocarbons can be gaseous,liquid, or solid under normal conditions of temperature and pressure,depending on the number and arrangement of carbon atoms in themolecules.

Crude oils vary widely in their physical and chemical properties fromone geographical region to another and from field to field. Crude oilsare usually classified into three groups according to the nature of thehydrocarbons they contain: paraffinic, naphthenic, asphaltic, and theirmixtures. The differences are due to the different proportions of thevarious molecular types and sizes. One crude oil can contain mostlyparaffins, another mostly naphthenes. Whether paraffinic or naphthenic,one can contain a large quantity of lighter hydrocarbons and be mobileor contain dissolved gases; another can consist mainly of heavierhydrocarbons and be highly viscous, with little or no dissolved gas.Crude oils can also include heteroatoms containing sulfur, nitrogen,nickel, vanadium and other elements in quantities that impact therefinery processing of the crude oil fractions. Light crude oils orcondensates can contain sulfur in concentrations as low as 0.01 W %; incontrast, heavy crude oils can contain as much as 5-6 W %. Similarly,the nitrogen content of crude oils can range from 0.001-1.0 W %.

The nature of the crude oil governs, to a certain extent, the nature ofthe products that can be manufactured from it and their suitability forspecial applications. A naphthenic crude oil will be more suitable forthe production of asphaltic bitumen, a paraffinic crude oil for wax. Anaphthenic crude oil, and even more so an aromatic one, will yieldlubricating oils with viscosities that are sensitive to temperature.However, with modern refining methods there is greater flexibility inthe use of various crude oils to produce many desired type of products.

A crude oil assay is a traditional method of determining the nature ofcrude oils for benchmarking purposes. Crude oils are subjected to trueboiling point (TBP) distillations and fractionations to providedifferent boiling point fractions. The crude oil distillations arecarried out using the American Standard Testing Association (ASTM)Method D 2892. Common fractions and their corresponding nominal boilingpoints or boiling point ranges are given in Table 1.

The yields, composition, physical and indicative properties of thesecrude oil fractions, where applicable, are then determined during thecrude assay work-up calculations. Typical compositional and propertyinformation obtained from a crude oil assay is given in Table 2.

Due to the number of distillation cuts and the number of analysesinvolved, the crude oil assay work-up is both costly and time consuming.In a typical refinery, crude oil is first fractionated in theatmospheric distillation column to separate sour gas and lighthydrocarbons, including methane, ethane, propane, butanes and hydrogensulfide, naphtha (for instance having a nominal boiling point range ofabout 36-180° C.), kerosene (for instance having a nominal boiling pointrange of about 180-240° C.), gas oil (for instance having a nominalboiling point range of about 240-370° C.) and atmospheric residue (forinstance having a nominal boiling point range of about >370° C.). Theatmospheric residue from the atmospheric distillation column is eitherused as fuel oil or sent to a vacuum distillation unit, depending on theconfiguration of the refinery. The principal products obtained fromvacuum distillation are vacuum gas oil (for instance having a nominalboiling point range of about 370-520° C.) and vacuum residue (forinstance having a nominal boiling point range of about >520° C.). Crudeassay data is conventionally obtained from individual analysis of thesecuts, separately for each type of data sought for the assay (that is,elemental composition, physical property and indicative property), tohelp refiners to understand the general composition of the crude oilfractions and properties so that the fractions can be processed mostefficiently and effectively in an appropriate refining unit. Indicativeproperties are used to determine the engine/fuel performance orusability or flow characteristic or composition.

Whole Crude Oil Properties

Many properties are routinely measured for crudes. Some of the mostcommon factors affecting crude oil handling, processing, and valueinclude the following: density; viscosity; pour point; Reid vaporpressure (RVP); carbon residue; sulfur; nitrogen; metals; salt content;hydrogen sulfide; Total Acidity Number (TAN). These are described inmore detail below:

-   -   Density, measured for example by the ASTM D287 method, is the        weight of a substance for a given unit of volume. Density of        crude oil or crude products is measured as specific gravity        comparing the density of the crude or product to the density of        water (usually expressed as gm/cc) or API gravity (° API or        degrees API).    -   Viscosity, measured for example by the ASTM D 445 method, is the        measure of the resistance of a liquid to flow, thereby        indicating the pumpability of the oil. Kinematic viscosity is        the viscosity of the material divided by the density (specific        gravity) of the material at the temperature of viscosity        measurement; kinematic viscosity is commonly measured in stokes        (St) or centistokes (cSt).    -   Pour point, measured for example by the ASTM D97 method, is the        temperature, to the next 5° F. increment, above which an oil or        distillate fuel becomes solid. The pour point is also the lowest        temperature, in 5° F. increments, at which the fluid will flow.        After preliminary heating, the sample is cooled at a specified        rate and examined at intervals of 3° C. for flow        characteristics. The lowest temperature at which movement of the        specimen is observed is recorded as the pour point.    -   Reid vapor pressure (RVP), measured for example by the ASTM D323        method, is the measure of the vapor pressure exerted by an oil,        mixed with a standard volume ratio of air, at 100° F. (38° C.).    -   Carbon residue, measured for example by the ASTM D189, D4536        methods, is the percentage of carbon by weight for coke,        asphalt, and heavy fuels found by evaporating oil to dryness        under standard laboratory conditions. Carbon residue is        generally termed Conradson Carbon Residue, or CCR.    -   Sulfur is the percentage by weight, or in parts per million by        weight, of total sulfur contained in a liquid hydrocarbon        sample. Sulfur must be removed from refined product to prevent        corrosion, protect catalysts, and prevent environmental        pollution. Sulfur is measured, for example, by ASTM D4294,        D2622, D5453 methods for gasoline and diesel range hydrocarbons.    -   Nitrogen, measured for example by the ASTM D4629, D5762 methods,        is the weight in parts per million, of total nitrogen contained        in a liquid hydrocarbon sample. Nitrogen compounds are also        catalyst poisons.    -   Various metals (arsenic, lead, nickel, vanadium, etc.) in a        liquid hydrocarbon are potential process catalyst poisons. They        are measured by Induced Coupled Plasma and/or Atomic Absorption        Spectroscopic methods, in ppm.    -   Salt is measured, for example, by the ASTM D3230 method and is        expressed as pounds of salt (NaCl) per 1000 barrels of crude.        Salts are removed prior to crude oil distillation to prevent        corrosion and catalyst poisoning.    -   Hydrogen sulfide (H₂S) is a toxic gas that can be evolved from        crude or products in storage or in the processing of crude.        Hydrogen sulfide dissolved in a crude stream or product stream        is measured in ppm.    -   Total acidity is measured, for example, by the ASTM methods,        D664, D974, and is a measure of the acidity or alkalinity of an        oil. The number is the mass in milligrams of the amount of acid        (HCl) or base (KOH) required to neutralize one gram of oil.

These properties affect the transportation and storage requirements forcrudes, define the products that can be extracted under variousprocessing schemes, and alert us to safety and environmental concerns.Each property can also affect the price that the refiner is willing topay for the crude. In general, light, low sulfur crudes are worth morethan heavy, high sulfur crudes because of the increased volume ofpremium products (gasoline, jet fuel, and diesel) that are availablewith minimum processing.

Crude Assays

A crude assay is a set of data that defines crude composition andproperties, yields, and the composition and properties of fractions.Crude assays are the systematic compilation of data defining compositionand properties of the whole crude along with yields and composition andproperties of various boiling fractions. For example, a conventionalassay method requires approximately 20 liters of crude oil betransported to a laboratory, which itself can be time-consuming andexpensive, and then distilled to obtain the fractions and then haveanalysis performed on the fractions. This systematic compilation of dataprovides a common basis for the comparison of crudes. The consistentpresentation of data allows us to make informed decisions as to storageand transportation needs, processing requirements, product expectations,crude relative values, and safety and environmental concerns. It alsoallows us to monitor crude quality from a single individual source overa period of time.

Crude oils or fractions are evaluated and compared using some of the keyproperties that are indicative of their performance in engines. Theseare the cetane number, the cloud point, the pour point (discussedabove), the aniline point, and the flash point. In instances where thecrude is suitable for production of gasoline, the octane number isanother key property. These are described individually herein.

The cetane number of diesel fuel oil, determined by the ASTM D613method, provides a measure of the ignition quality of diesel fuel; asdetermined in a standard single cylinder test engine; which measuresignition delay compared to primary reference fuels. The higher thecetane number; the easier the high-speed; direct-injection engine willstart; and the less white smoking and diesel knock after start-up are.The cetane number of a diesel fuel oil is determined by comparing itscombustion characteristics in a test engine with those for blends ofreference fuels of known cetane number under standard operatingconditions. This is accomplished using the bracketing hand wheelprocedure which varies the compression ratio (hand wheel reading) forthe sample and each of the two bracketing reference fuels to obtain aspecific ignition delay, thus permitting interpolation of cetane numberin terms of hand wheel reading.

The cloud point, determined by the ASTM D2500 method, is the temperatureat which a cloud of wax crystals appears when a lubricant or distillatefuel is cooled under standard conditions. Cloud point indicates thetendency of the material to plug filters or small orifices under coldweather conditions. The specimen is cooled at a specified rate andexamined periodically. The temperature at which cloud is first observedat the bottom of the test jar is recorded as the cloud point. This testmethod covers only petroleum products and biodiesel fuels that aretransparent in 40 mm thick layers, and with a cloud point below 49° C.

The aniline point, determined by the ASTM D611 method, is the lowesttemperature at which equal volumes of aniline and hydrocarbon fuel orlubricant base stock are completely miscible. A measure of the aromaticcontent of a hydrocarbon blend is used to predict the solvency of a basestock or the cetane number of a distillate fuel. Specified volumes ofaniline and sample, or aniline and sample plus n-heptane, are placed ina tube and mixed mechanically. The mixture is heated at a controlledrate until the two phases become miscible. The mixture is then cooled ata controlled rate and the temperature at which two separate phases areagain formed is recorded as the aniline point or mixed aniline point.

The flash point, determined by ASTM D56, D92, D93 methods, is theminimum temperature at which a fluid will support instantaneouscombustion (a flash) but before it will burn continuously (fire point).Flash point is an important indicator of the fire and explosion hazardsassociated with a petroleum product.

The octane number, determined by the ASTM D2699 or D2700 methods, is ameasure of a fuel's ability to prevent detonation in a spark ignitionengine. Measured in a standard single-cylinder;variable-compression-ratio engine by comparison with primary referencefuels. Under mild conditions, the engine measures research octane number(RON), while under severe conditions, the engine measures motor octanenumber (MON). Where the law requires posting of octane numbers ondispensing pumps, the antiknock index (AKI) is used. This is thearithmetic average of RON and MON, (R+M)/2. It approximates the roadoctane number, which is a measure of how an average car responds to thefuel.

New rapid, and direct methods to help better understand crude oilcompositions and properties from analysis of whole crude oil will saveproducers, marketers, refiners and/or other crude oil users substantialexpense, effort and time. Therefore, a need exists for an improvedsystem and method for determining indicative properties of crude oilfractions from different sources.

SUMMARY

Systems and methods are disclosed for providing virtual assays includingassigned assay values pertaining to an oil sample subject to analysis,and its fractions, based on data obtained by analytic characterizationof the oil sample without fractionation, and the density of the oilsample. The virtual assay of the oil sample provides a full range ofinformation about fractions of the oil sample including naphtha, gasoil, vacuum gas oil, residue, and other information about the propertiesof the oil sample. This virtual assay is useful for producers, refiners,and marketers to benchmark the oil quality and, as a result, evaluatethe oils without performing the customary extensive and time-consumingcrude oil assays.

In an embodiment, the present disclosure is directed to a method forproducing a virtual assay of an oil sample, wherein the oil sample ischaracterized by a density, selected from the group consisting of crudeoil, bitumen and shale oil, and characterized by naphtha, gas oil,vacuum gas oil and vacuum residue fractions. Time of flight massspectroscopy (TOF-MS) data indicative of cumulative mass fraction datafor a solution of the oil sample without distillation in a TOF-MSsolvent, is entered into a computer. An analytical value (AV) iscalculated and assigned as a function of the TOF-MS data. Virtual assaydata of the oil sample and the naphtha, gas oil, vacuum gas oil andvacuum residue fractions is calculated and assigned as a function of theAV and the density of the oil sample. The virtual assay data comprises aplurality of assigned data values.

In certain embodiments, the virtual assay data comprises: a plurality ofassigned assay data values pertaining to the oil sample including one ormore of the aromatic content, C5-asphaltenes content, elementalcompositions of sulfur and nitrogen, micro-carbon residue content, totalacid number and viscosity, a plurality of assigned assay valuespertaining to the vacuum residue fraction of the oil sample includingone or more of the elemental composition of sulfur and micro-carbonresidue content; a plurality of assigned assay values pertaining to thevacuum gas oil fraction of the oil sample including one or both of theelemental compositions of sulfur and nitrogen; a plurality of assignedassay values pertaining to the gas oil fraction of the oil sampleincluding one or more of the elemental compositions of sulfur andnitrogen, viscosity, and indicative properties including aniline point,cetane number, cloud point and/or pour point; and a plurality ofassigned assay values pertaining to the naphtha fraction of the oilsample including one or more of the aromatic content, elementalcomposition of hydrogen and/or sulfur, paraffin content and octanenumber.

In certain embodiments, the virtual assay data also comprises: yields offractions from the oil sample as mass fractions of boiling point ranges,including one or more of naphtha, gas oil, vacuum gas oil and vacuumresidue; composition information of hydrogen sulfide and/or mercaptansin the oil sample and/or its fractions; elemental compositions of one ormore of carbon, hydrogen, nickel, and vanadium; physical properties ofthe oil sample and/or its fractions including one or more of API gravityand refractive index; and/or indicative properties of the oil sampleand/or its fractions including one or more of flash point, freezingpoint and smoke point.

In certain embodiments, the method further comprises operating a time offlight mass spectrometer to obtain the TOF-MS data over a range ofmass-to-charge ratios, by analyzing the solution of the oil samplewithout distillation in the TOF-MS mass spectroscopy solvent.

In certain embodiments, each assay value is determined by amulti-variable polynomial equation with predetermined constantcoefficients developed using linear regression techniques, whereincorresponding variables are the AV and the density of the oil sample.

In certain embodiments, the analytical value is an index derived from aweighted average of masses derived from the TOF-MS data.

In an embodiment, the present disclosure is directed to a system forproducing a virtual assay of an oil sample, wherein the oil sample ischaracterized by a density, is selected from the group consisting ofcrude oil, bitumen and shale oil, and is characterized by naphtha, gasoil, vacuum gas oil and vacuum residue fractions. The system comprises atime of flight mass spectrometer that outputs TOF-MS data, anon-volatile memory device, a processor coupled to the non-volatilememory device, and first and second calculation modules that are storedin the non-volatile memory device and that are executed by theprocessor. The non-volatile memory device stores the calculation moduleand data, the data including the TOF-MS data that is indicative ofcumulative mass fraction data for a solution of the oil sample withoutdistillation in a TOF-MS solvent. The first calculation module containssuitable instructions to calculate, as a function of the TOF-MS data,one or more analytical values (AV). The second calculation modulecontains suitable instructions to calculate, as a function of the one ormore AVs and the density of the oil sample, a plurality of assigned datavalues as the virtual assay pertaining to the overall oil sample, andthe naphtha, gas oil, vacuum gas oil and vacuum residue fractions of theoil sample.

Still other aspects, embodiments, and advantages of these exemplaryaspects and embodiments, are discussed in detail below. Moreover, it isto be understood that both the foregoing information and the followingdetailed description are merely illustrative examples of various aspectsand embodiments, and are intended to provide an overview or frameworkfor understanding the nature and character of the claimed aspects andembodiments. The accompanying drawings are included to provideillustration and a further understanding of the various aspects andembodiments, and are incorporated in and constitute a part of thisspecification. The drawings, together with the remainder of thespecification, serve to explain principles and operations of thedescribed and claimed aspects and embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is process flow diagram of steps used to implement the methoddescribed herein for providing virtual assays of an oil sample such ascrude oil based on time of flight mass spectroscopy (TOF-MS).

FIG. 2A is a graphic plot of typical TOF-MS data for a crude oil samplewith an API gravity of 28.8°, where the intensity is plotted against them/z values.

FIG. 2B is a graphic plot of m/z ratio versus the cumulative massfraction for a number of crude oil samples.

FIG. 3 is a process flow diagram of steps used in an example herein toprovide a virtual assay of a crude oil sample based on TOF-MS.

FIG. 4 is a block diagram of a component of a system for implementingthe invention, according to one embodiment.

DETAILED DESCRIPTION

Systems and methods are disclosed for providing virtual assays of an oilsample such as crude oil based on time of flight mass spectroscopy(TOF-MS) carried out on the oil sample, and the density of the oilsample. The virtual assay provides a full range of information aboutfractions of the oil sample including naphtha, gas oil, vacuum gas oil,vacuum residue, and other information about the properties of the oilsample. Using the system and method herein, the virtual assay datapertaining to these several fractions of the oil sample and the oilsample itself are obtained without fractionation of the oil sample intothe several components.

Concerning the naphtha fraction, assigned assay values for the virtualassay include: elemental composition values included in the virtualassay comprise one or more of hydrogen content, aromatic content,paraffin content and sulfur content; and an indicative property includedin the virtual assay comprises an octane number. Concerning the gas oilfraction, assigned assay values for the virtual assay include: elementalcomposition values included in the virtual assay comprise one or more ofsulfur content and nitrogen content; physical properties included in thevirtual assay comprises viscosity and pour point; and indicativeproperties included in the virtual assay comprise one or more of anilinepoint, cetane number and cloud point. Concerning the vacuum gas oilfraction, assigned assay values for the virtual assay include: elementalcomposition values included in the virtual assay comprise one or more ofsulfur content, nitrogen content and micro carbon residue content.Concerning the vacuum residue, assigned assay values for the virtualassay include: elemental composition values included in the virtualassay comprise one or more of sulfur content and micro carbon residuecontent. Concerning the full range of the oil sample, assigned assayvalues for the virtual assay include: elemental composition valuesincluded in the virtual assay comprise one or more of asphaltenecontent, sulfur content, nitrogen content and total acids content (totalacid number, mg KOH/100 g); and physical properties included in thevirtual assay comprises viscosity and pour point.

In certain embodiments of the virtual assay provided herein, the“naphtha fraction” refers to a straight run fractions from atmosphericdistillation containing hydrocarbons having a nominal boiling range ofabout 20-205, 20-193, 20-190, 20-180, 20-170, 32-205, 32-193, 32-190,32-180, 32-170, 36-205, 36-193, 36-190, 36-180 or 36-170° C.; the “gasoil fraction” refers to a straight run fractions from atmosphericdistillation containing hydrocarbons having a nominal boiling range ofabout 170-400, 170-380, 170-370, 170-360, 180-400, 180-380, 180-370,180-360, 190-400, 190-380, 190-370, 190-360, 193-400, 193-380, 193-370or 193-360° C.; the “vacuum gas oil fraction” refers to a straight runfractions from vacuum distillation containing hydrocarbons having anominal boiling range of about 360-565, 360-550, 360-540, 360-530,360-520, 360-510, 370-565, 370-550, 370-540, 370-530, 370-520, 370-510,380-565, 380-550, 380-540, 380-530, 380-520, 380-510, 400-565, 400-550,400-540, 400-530, 400-520 or 400-510° C.; and “vacuum residue” refers tothe bottom hydrocarbons from vacuum distillation having an initialboiling point corresponding to the end point of the VGO rangehydrocarbons, for example about 510, 520, 530, 540, 550 or 565° C., andhaving an end point based on the characteristics of the crude oil feed.

The system and method is applicable for naturally occurring hydrocarbonsderived from crude oils, bitumens or shale oils, and heavy oils fromrefinery process units including hydrotreating, hydroprocessing, fluidcatalytic cracking, coking, and visbreaking or coal liquefaction.Samples can be obtained from various sources, including an oil well,core cuttings, oil well drilling cuttings, stabilizer, extractor, ordistillation tower. In certain embodiments system and method isapplicable for crude oil, whereby a virtual assay is obtained using thesystems and methods herein without the extensive laboratory workrequired for distillation and analysis of each of the individualfractions.

Referring to FIG. 1 , a process flow diagram of steps carried out toobtain a virtual assay 195 is provided. Prior to carrying out the stepsoutlined in FIG. 1 , a set of constants is obtained for each of theelemental composition values/physical properties/indicative propertiesto be calculated using the process and system disclosed herein to obtaina virtual assay, represented as dataset 105. The set of constants can bedeveloped, for instance by linear regression techniques, based onempirical data of a plurality of crude oil assays and analyses usingconventional techniques including distillation and industry-establishedtesting methods to obtain the crude oil assay data. Examples of sets ofconstants used for calculating assigned assay values to produce thevirtual assay 195 based on various analytic characterization techniquesare provided herein.

At step 110, the density if the oil sample is provided (steps forobtaining this density are not shown and can be carried out as is known,in certain embodiments a 15° C./4° C. density in units of kilograms perliter using the method described in ASTM D4052); this density value canbe stored in memory with other data pertaining to the oil sample, orconveyed directly to the one or more steps as part of the functionsthereof. In step 115, if necessary, the oil sample is prepared for aparticular analytic characterization technique (shown in dashed lines asoptional). In step 120, analytic characterization of the oil sample, orthe oil sample prepared as in step 115, without fractionation, iscarried out. As a result, analytic characterization data 125 isobtained.

In step 130, the analytic characterization data 125 is used to calculateone or more analytical values 135, which are one common analytical valueor a common set of analytical values used in subsequent steps tocalculate a plurality of different elemental composition values/physicalproperties/indicative properties that make up the virtual assay. In theembodiments herein the one common analytical value or common set ofanalytical values is an index or plural index values, also referred toas a TOF-MS index or TOFMSI, derived from a weighted average of massesderived from the TOF-MS data from time of flight mass spectroscopycarried out on the oil sample.

Steps 140, 150, 160, 170 and 180 are used to calculate and assign aplurality of different elemental composition values/physicalproperties/indicative properties that make up the virtual assay 195, foreach of a total oil sample, a naphtha fraction, a gas oil fraction, avacuum gas oil fraction and a vacuum residue fraction, respectively.Each of the steps produces corresponding assigned assay values for thevirtual assay 195, include including assigned assay values 145pertaining to the total oil sample, assigned assay values 155 pertainingto a naphtha fraction, assigned assay values 165 pertaining to a gas oilfraction, assigned assay values 175 pertaining to a vacuum gas oilfraction and assigned assay values 185 pertaining to a vacuum residuefraction.

In certain embodiments, the steps are carried out in any predeterminedsequence, or in no particular sequence, depending on the procedures inthe calculation modules. In certain embodiments, the steps are carriedout in parallel. The process herein uses a common analytical value, inconjunction with the set of constants and the density of the oil sample,for each of the assigned assay values (elemental compositionvalues/physical properties/indicative properties) in the given virtualoil sample assay 195 produced at step 190. For instance, each of thesteps 140, 150, 160, 170 and 180 are carried in any sequence and/or inparallel out as show using the equations herein for various analyticalvalues or sets of analytical values.

The assigned assay values from each of the fractions and the total oilsample are compiled and presented as a virtual assay 195, which can be,for instance, printed or rendered on a display visible to, or otherwisecommunicated to, a user to understand the composition and properties ofthe crude. With the virtual assay 195, users such as customers,producers, refiners, and marketers can benchmark the oil quality. Thevirtual assay 195 can be used to guide decisions related to anappropriate refinery or refining unit, for processing the oil from whichthe oil sample is obtained, and/or for processing one or more of thefractions thereof. In addition the assigned assay values including theindicative properties are used to determine the engine/fuel performanceor usability or flow characteristic or composition. This can beaccomplished using the method and system herein without performing thecustomary extensive and time-consuming crude oil assays.

The assigned assay values for the virtual assay herein are calculated asa function of one or more analytical values, and the density of the oilsample, as denoted at (1).

AD=f(ρ,AV)  (1)

where:

-   -   AD is the assigned assay value (for example a value and/or        property representative of an elemental composition value, a        physical property or an indicative property); and    -   AV is an analytical value of the oil sample, wherein AV can be a        single analytical value, or wherein AV can be AV(1) . . . AV(n)        as plural analytical values of the oil sample, wherein n is an        integer of 2 or more, in certain embodiments 2, 3 or 4; and    -   ρ is the density of the oil sample, in certain embodiments a 15°        C./4° C. density in units of kilograms per liter using the        method described in ASTM D4052.

According to an embodiment of the system and method described furtherherein, an analytical value AV is a single value, an index value derivedfrom the weighted average of masses derived from the TOF-MS data fromtime of flight mass spectroscopy carried out on the oil sample,represented herein as a TOF-MS index or TOFMSI. Advantageously, themethod and system herein deploy analytical characterization by TOF-MS tocarry out analysis of the oil sample without fractionating, obtain ananalytical value based on the TOF-MS analysis of the oil sample, and usethe analytical value or set of analytical values, and the density of theoil sample, to obtain a plurality of assigned assay values (for examplea value and/or property representative of an elemental compositionvalue, a physical property or an indicative property) to produce avirtual assay of the oil sample.

In one embodiment, an assigned assay value is calculated used a thirddegree multi variable polynomial equation including the analyticalvalue, the density of the oil sample, and a plurality of constants, forexample predetermined by linear regression, as denoted in equation (2a).

AD=K _(AD) +X1_(AD) *AV+X2_(AD) *AV ² +X3_(AD) *AV ³ +X4_(AD)*ρ*AV  (2a)

where:

-   -   AD is the assigned assay value (for example a value and/or        property representative of an elemental composition value, a        physical property or an indicative property);    -   AV is an analytical value of the oil sample;    -   ρ is the density of the oil sample, in certain embodiments a 15°        C./4° C. density in units of kilograms per liter using the        method described in ASTM D4052; and    -   K_(AD), X1_(AD), X2_(AD), X3_(AD), and X4_(AD) are constants,        for instance, developed using linear regression techniques (note        that in certain embodiments and for certain assigned assay        values, one or more of K_(AD), X1_(AD), X2_(AD), X3_(AD) and        X4_(AD) is/are not used, or is/are zero).

In another embodiment, an assigned assay value is calculated used athird degree multi variable polynomial equation including the analyticalvalue, the density of the oil sample, and a plurality of constants, forexample predetermined by linear regression, as denoted in equation (2b).

AD=K _(AD) +X1_(AD) *ρ+X2_(AD)*ρ² +X3_(AD)*ρ³ +X4_(AD) *AV+X5_(AD) *AV ²+X6_(AD) *AV ³ +X7_(AD) *ρ*AV  (2b)

where:

-   -   AD is the assigned assay value (for example a value and/or        property representative of an elemental composition value, a        physical property or an indicative property);    -   AV is an analytical value of the oil sample;    -   ρ is the density of the oil sample, in certain embodiments a 15°        C./4° C. density in units of kilograms per liter using the        method described in ASTM D4052; and    -   K_(AD), X1_(AD), X2_(AD), X3_(AD), X4_(AD), X5_(AD), X6_(AD) and        X7_(AD) are constants, for instance, developed using linear        regression techniques (note that in certain embodiments and for        certain assigned assay values, one or more of K_(AD), X1_(AD),        X2_(AD), X3_(AD), X4_(AD), X5_(AD), X6MAD and X7_(AD) is/are not        used, or is/are zero).

Assigned assay values that can be determined and included for display orpresentation to the user in the virtual assay produced using the systemsand methods herein include one or more of:

-   -   elemental composition of the oil sample and its fractions        including the sulfur and nitrogen compositions;    -   TAN (total acid number) of the oil sample;    -   composition of certain desirable and undesirable compounds or        types of compounds present in the oil sample and/or its        fractions, including one or more of, micro carbon residue,        C5-asphaltenes (the yield of asphaltenes using separation based        on C5 paraffins as deasphalting solvent), paraffins, aromatics,        and naphthenes;    -   physical properties of the oil sample and/or its fractions        including viscosity such as kinematic viscosity;    -   indicative properties of the oil sample and/or its fractions,        including one or more of cloud point, pour point, research        octane number, cetane number and aniline point.        In certain embodiments, the assigned assay values can include        yields of fractions from the oil sample, for example as mass        fractions of boiling point ranges, including one or more of        naphtha, gas oil, vacuum gas oil and vacuum residue. In certain        embodiments, the assigned assay values can include composition        information of hydrogen sulfide and/or mercaptans in the oil        sample and/or its fractions. In certain embodiments, the        assigned assay values can include elemental compositions of one        or more of carbon, hydrogen, nickel, and vanadium. In certain        embodiments, the assigned assay values can include physical        properties of the oil sample and/or its fractions including one        or more of API gravity and refractive index. In certain        embodiments, the assigned assay values can include indicative        properties of the oil sample and/or its fractions including one        or more of flash point, freezing point and smoke point.

In certain embodiments, a method for producing a virtual assay of anuncharacterized oil sample is provided. The uncharacterized oil sampleis characterized by a density, selected from the group consisting ofcrude oil, bitumen and shale oil, and characterized by naphtha, gas oil,vacuum gas oil and vacuum residue fractions. The virtual assay comprisesa plurality of assigned data values. The uncharacterized oil sample isobtained, for instance the sample being between one to two millilitersin volume and not subject to any fractionation. A plurality of knowndata values (corresponding to the assigned data values used in thevirtual assay) for known oil samples with known densities (which knownoil samples exclude the uncharacterized oil sample) are obtained. Thisdata is obtained from empirical data of a plurality of existing crudeoil assays and/or analyses using conventional techniques includingdistillation and industry-established testing methods. One or moreselected analytical techniques are carried out on the each of the knownoil samples, and one or more analytical values are calculated for eachof the known oil samples. The one or more selected analytical techniquesare carried out on the uncharacterized oil sample, and one or moreanalytical values are calculated for the uncharacterized oil sample.Constants of a polynomial equation are obtained, and the polynomialequation is used to determine a plurality of assigned data values thatmake up the virtual assay of the uncharacterized oil sample. Thepolynomial equation is a function of density and the one or moreanalytical values of the uncharacterized oil sample. The constants ofthe polynomial equation are determined using a fitting method to fit theplurality of known data values of the plurality of known oil samples tothe plurality of values of the density of the plurality of known oilsamples and the plurality of the one or more analytical values for theplurality of known oil samples.

Rather than relying on conventional techniques including distillationand laborious, costly and time-consuming analytical methods tomeasure/identify data regarding the crude oil and/or its fractionsincluding elemental composition, physical properties and indicativeproperties, as little as 1 gram of oil can be analyzed. From theanalysis of a relatively small quantity of the oil sample, the assignedassay values are determined by direct calculation, without requiringdistillation/fractionization.

TOF-MS is the analytic characterization technique that is employed on arelatively small quality of an oil sample, such as crude oil. Ananalytical value, comprising or consisting of the TOF-MS index, fromsaid analytic characterization technique, is used to calculate andassign physical and indicative properties that are the requisite datafor the virtual oil sample assay. The method and system provides insightinto the properties of oil sample, the naphtha fraction, the gas oilfraction, the vacuum gas oil fraction, and the vacuum residue fraction,without fractionation/distillation (conventional crude oil assays). Thevirtual oil sample assay will help producers, refiners, and marketersbenchmark the oil quality and, as a result, evaluate (qualitatively andeconomically) the oils without going thru costly and time consumingcrude oil assays. Whereas a conventional crude oil assay method couldtake up to two months, the method and system herein can provide avirtual assay in less than one day and in certain embodiments less than1-2 hours. In addition, the method and system herein carried out at 1%or less of the cost of a traditional assay requiringdistillation/fractionization follows by individual testing for each typeof property and for each fraction.

The systems and methods herein are implemented using an index derivedfrom TOF-MS data as an analytical value in equations (1), and (2a) or(2b) above. Embodiments of such methods are described in the context ofassigning an indicative property of a fraction of an oil sample andcertain properties of whole crude oil in commonly owned U.S. patentapplication Ser. No. 17/183,872 filed on Feb. 24, 2021, entitledCharacterization of Crude Oil By Time of Flight Mass Spectrometry, whichis incorporated by reference herein in its entirety. In the systems andmethods herein, and with reference to FIG. 1 , a virtual assay 195 of anoil sample is obtained at step 190, wherein each assigned data value ofthe virtual assay is a function of an index derived from TOF-MS databased on analysis of the oil sample, or in another embodiment as afunction of the density of the oil sample and of an index derived fromTOF-MS data based on analysis of the oil sample. The virtual assayprovides information about the oil sample and fractions thereof to helpproducers, refiners, and marketers benchmark the oil quality and, as aresult, evaluate the oils without performing the customary extensive andtime-consuming crude oil assays involving fractionation/distillation andseveral individual and discrete tests.

The oil sample is optionally prepared, step 115, by dissolving the oilsample in a suitable TOF-MS solvent known for use in TOF-MS operations.An example of a suitable TOF-MS solvent is toluene, but other solventsknown in the art for preparing TOF-MS samples are also suitable. Incertain embodiments, the oil sample can be directly analyzed, and step115 is avoided, and accordingly step 115 is shown in dashed lines inFIG. 1 . In a typical operation, crude oil samples are prepared andanalyzed by atmospheric pressure photo ionization (APPI) time of flightmass spectrometry (TOF-MS). Stock solutions of crude oil samples wereprepared by homogenizing for 20 s on the Vortexer mixer at 2000 rpm. Thehomogenized sample was then diluted in analytical grade toluene to aconcentration of 0.10 mg/g. A Mass spectra of each samples was acquired,for example on a 6230 TOF mass spectrometer (Agilent Technologies), orequivalent, equipped with atmospheric pressure photo ionization (APPI)source. In a typical operation, for each analysis of an oil sample, theoperator tunes the spectrometer settings to optimize performance.

The solution or oil sample is analyzed, step 120, and TOF-MS data isobtained. Step 120 is carried out and the analytic characterizationdata, the TOF-MS data, is entered into the computer system 400 describedherein with respect to FIG. 4 , for example stored into non-volatilememory of the via data storage memory 480, represented as the analyticcharacterization data 125. This can be carried out by a raw datareceiving module stored in the program storage memory 470.

Analytical values are obtained that include the cumulative massfraction, or spectral intensity or abundance, of each m/z value. In step130, the cumulative mass fraction is used to calculate one or moreanalytical values 135, which can be an index, also referred to as aTOFMSI. Step 130 is carried out, for example, by execution by theprocessor 420 of one or more modules stored in the program storagememory 470, and the analytical values 135, the index, is stored in theprogram storage memory 470 or the data storage memory 480, for use inthe modules determining the assigned data values. In certainembodiments, the density of the oil sample, provided at step 110, isstored in the program storage memory 470 or the data storage memory 480,for use in the modules determining the assigned data values; this can becarried out by a raw data receiving module stored in the program storagememory 470.

The assigned data values including virtual assay data 145 pertaining tothe total oil sample, virtual assay data 155 pertaining to a naphthafraction, virtual assay data 165 pertaining to a gas oil fraction,virtual assay data 175 pertaining to a vacuum gas oil fraction andvirtual assay data 185 pertaining to vacuum residue fraction, areobtained according to the functions described herein, for example, inthe corresponding steps 140, 150, 160, 170 and 180. The constants usedfor determining the assigned data values, are provided at step 105 andare stored in the program storage memory 470 or the data storage memory480, for use in the modules determining the assigned data values. Thesteps for obtaining the assigned data values are carried out, forexample, by execution by the processor 420 of one or more modules storedin the program storage memory 470, and the several assigned data valuesare calculated and stored in the data storage memory 480, presented onthe display 410 and/or presented to the user by some other output devicesuch as a printer.

TOF-MS is a mass spectrometric method that is based on the principlethat ions with the same energy but different masses travel withdifferent velocities. The mass-to-charge ratio (m/z) is determined bythe time an ion takes to arrive at the detector. Ions formed areaccelerated by an electrostatic field over a distance to the detector,where the lighter ions arrive earlier in time than the heavier ions,since the velocity of the ions is dependent on their m/z ratio. The massof each ion can be determined by measuring the flight time of the ion. Amass spectrum is recorded as a signal from the detector. a mass spectrais obtained by a suitable known or to be developed TOF-MS instruments,and from this spectra signal intensity data is obtained (for example,Y-axis in FIG. 2A, which shows the TOF-MS data for a sample with an APIGravity of 28.8°) as a function of the m/z of ions (X-axis in FIG. 2A).In certain embodiments, the TOF-MS data can be over a mass-to-chargeratio range of 90-3000 or 220-3000 m/z.

TOF-MS includes two main components: an ionization source and a massanalyzer. The ionization source ionizes molecules, while the massanalyzer determines the mass-to-charge ratio (m/z) of ions. A number ofionization sources have been used in TOF-MS, with some being preferablefor gases, others for liquids, and others for solids. Ionization sourcesfor TOF-MS include electron ionization (EI), which uses a glowingfilament, which may break down the molecules under study. Inductivelycoupled plasma ionization (ICP) is a destructive technique which appliesheat to reduce a sample to its atomic components. Chemical ionization(CI), a subset of EI, adds gases such as methane, isobutane, or ammonia,producing results that are less damaging to the molecules under study.Direct analysis in real time (DART) ionizes samples at atmosphericpressure using an electron beam. Matrix-assisted, laser desorptionionization (MALDI) is a solid phase process that uses laser energy toionize molecules off a metal target plate.

Electrospray ionization (ESI), is a liquid phase process that produces afine mist of charged droplets that are dried in a countercurrentmovement of heated gas to produce charge analytes in the gas phase.Field desorption/field ionization (FD/FI) relies on doping the sampleonto and emitter, and then combines the processes of ionization andsubsequent desorption of the ions formed on the surface of a fieldemitter into the mass spectrometer.

TOF-MS of petroleum samples frequently relies on atmospheric pressurephotoionization (APPI), which uses a photon discharge fromhigh-intensity ultraviolet light to ionize the solvent gas, which inturn ionizes the sample molecules. APPI works well with highly non-polararomatic molecules like alkyl substituted benzenes, naphthalenes andanthracenes, and FD/FI works well with paraffinic or naphthenicmolecules as well as aromatic molecules.

Thus, for the purpose of petroleum characterization, TOF-MS is conductedusing preferably APPI or FD/FI. For APPI operation, a petroleum sampleis diluted in an appropriate solvent such as toluene, and infused intothe spectrometer. The diluted sample is delivered via syringe pumpdirectly into the APPI source. For FD/FI operation, the diluted sampleis adsorbed via syringe onto a FD/FI emitter mounted on a FD probe.Immediately after the probe is transferred into the ion source of theTOF MS the analysis is started by ramping the emitter current to desorbthe sample.

One can thus interpret that m/z values from the TOF-MS are also the mass(m) values in atomic mass units (amu). The m/z raw data, i.e., theTOF-MS data, can be converted to show the cumulative mass fraction, orspectral abundance, of each m/z value. In other words, the TOF-MS datais representative of cumulative mass fraction data. In general, in orderto convert to cumulative mass fraction for each m/z value, the intensityfor the second m/z value in the original TOF-MS data set is added to theintensity of the first m/z value; the intensity for the third m/z valueis added to the sum of the first two m/z values, and so on. Thosecumulative values are normalized by dividing by the sum of all the peaksin the original TOF-MS data set. For example, a cumulative mass fractionvalue of 0.20 corresponds to the mass value at the 20% percentile oftotal peak intensity in the original TOF-MS data set. Thus, in thepetroleum industry, TOF-MS is conducted using ESI, and preferably theAPPI variant of ESI. A petroleum sample is diluted in an appropriatesolvent and infused into the spectrometer. The diluted sample isdelivered via syringe pump directly into the APPI source.

The determination of the assigned data is carried out using variablescomprising or consisting of the TOFMSI of the oil sample and the densityof the oil sample.

AD=f(ρ,TOFMSI))  (3)

where:

-   -   AD is the assigned data value (for example a value and/or        property representative of an elemental composition value, a        physical property or an indicative property);    -   TOFMSI=index derived from a weighted average of masses derived        from the TOF-MS data and    -   ρ is the density of the oil sample, in certain embodiments a 15°        C./4° C. density in units of kilograms per liter using the        method described in ASTM D4052.

For example, this relationship can be expressed as follows:

AD=K _(AD) +X1_(AD) *ρ+X2_(AD)*ρ² +X3_(AD)*ρ³+X4_(AD)*TOFMSI+X5_(AD)*TOFMSI² +X6_(AD)*TOFMSI³ +X7_(AD)*ρ*TOFMSI  (4)

where AD, TOFMSI and p are as in equation TOFMSI, and where:

-   -   K_(AD), X1_(AD), X2_(AD), X3_(AD), X4_(AD), X5_(AD), X6_(AD) and        X7_(AD) are constants, for instance, developed using linear        regression techniques, for each AD to be determined (note that        in certain embodiments and for certain assigned assay values,        one or more of K_(AD), X1_(AD), X2_(AD), X3_(AD), X4_(AD),        X5_(AD), X6_(AD) and X7_(AD) is/are not used, or is/are zero).

Using the equation (4), one or more assigned data values AD aredetermined using the density of the oil sample and the TOFMSI of the oilsample, as determined by TOFMSI data of the oil sample.

Table 3 lists assigned data for a virtual assay of an oil sample underinvestigation, with descriptions, abbreviations and units, for eachassigned data property for the naphtha fraction, the gas oil fraction,the vacuum gas oil fraction, the vacuum residue fraction and the overalloil sample. Table 3 further provides exemplary constants, for instance,developed using linear regression techniques, for plural assigned datavalues to be determined based on the density of the oil sample and theTOFMSI of the oil sample. These constants are used in the example belowwith the calculated values provided in Table 5 compared to the actualvalues as determined by a conventional crude oil assay.

The constants, for example as in Table 3, are stored as in step 105 inthe process flow diagram of FIG. 1 . These are used in one or morecalculation modules to obtain the virtual assay 195 of an oil sample asin step 190, in conjunction with the analytical values obtained step 130based upon TOF-MS data, the TOFMSI of the oil sample. In certainembodiments the constants are stored as in step 105, and the density isstored as in step 110; the constants are used in one or more calculationmodules to obtain the virtual assay 195 of an oil sample as in step 190,in conjunction with density of the oil sample stored in step 110 and theanalytical values obtained in step 130 from the TOF-MS data obtained instep 120, the TOFMSI of the oil sample. As shown, modules are separatedbased on the fraction for which assigned data values are obtained, butis it understood that they can be arranged in any manner so as toprovide all of the assigned data values required for the virtual assayof the oil sample.

In certain embodiments, the assigned data values including virtual assaydata 145 pertaining to the total oil sample, virtual assay data 155pertaining to a naphtha fraction, virtual assay data 165 pertaining to agas oil fraction, virtual assay data 175 pertaining to a vacuum gas oilfraction and virtual assay data 185 pertaining to a vacuum residuefraction. This data is obtained according to the function (3) describedabove (for example expressed as in equation (4) described above, forexample, with the corresponding modules/steps 140, 150, 160, 170 and180.

In certain embodiments, the analytical value obtained as in step 130 isa TOFMSI of the oil sample, as the index derived from a weighted averageof masses derived from the TOF-MS data, determined as follows:

$\begin{matrix}{({TOFMSI}) = \frac{\left\lbrack {{\sum}_{x,{y = 5},10,20,30,40,50,60,70,80,90,95}M_{x}*W_{y}} \right\rbrack}{\left\lbrack {{\sum}_{{y = 5},10,20,30,40,50,60,70,80,90,95}W_{y}} \right\rbrack}} & (5)\end{matrix}$

-   -   where:    -   M=mass, over a range of x percentage from 0 to 100; and    -   W=weight fraction of the mass, i.e., cumulative mass fraction        over a range y.

Example

Crude oil samples, including a crude oil sample as the oil sample underinvestigation, were analyzed by TOF-MS according to the methodsdescribed herein. FIG. 2A is a graphic plot of typical TOF-MS data for acrude oil sample with an API gravity of 28.8° where the intensity isplotted against the m/z values. The cumulative mass fraction for anumber of crude oil samples is shown in in FIG. 2B. The cumulative massfraction data for crude oil having an API gravity of 28.8° is presentedin Tables 4A and 4B. FIG. 3 shows a process flow chart of steps for amethod of obtaining assigned data based on TOF-MS data. In step 305,constants are obtained, for example corresponding to the data in Table3. In step 310, the density of the oil sample was obtained. In theexample, the oil sample was Arabian medium crude with a 15° C./4° C.density of 0.8828 Kg/L, determined using the method described in ASTMD4052.

In step 315, the oil sample (crude oil) was prepared. The oil sample wasoptionally prepared by homogenizing the sample for 20 seconds on theVortexer mixer at 2000 rpm. The homogenized sample was then diluted inanalytical grade toluene to a concentration of 0.10 mg/g.

At step 320, analytic characterization of the oil sample, withoutfractionation, was carried out. A sample of Arabian medium crude with adensity of 0.8828 Kg/l was analyzed by TOF-MS. Key parameters anddefault settings follow:

-   -   Solvent: toluene    -   Sample dilution: 1:1,000 to 1:100,000    -   Flow rate: 10 L/min to 40 μL/min    -   Nebulizer gas (N2) flow: 2 mL/min to 5 mL/min    -   Average Spectra: 60    -   Source Accumulation: 1 Hz    -   APPI Temperature 300-450° C., depending on sample    -   Skimmer 1 potential: 25 V to 65 V    -   Ion extraction potential: 140 V to 250 V    -   Low Mass: 90 to 220 m/z (amu)    -   High Mass: 3000 m/z (amu)

The analysis began when the diluted sample was delivered via a syringepump at a flow rate of 20 μL/min directly into the APPI source. A stableionizer spray was maintained for all samples. Gas flow rates (nebulizerand dry gas) were set to 8 L/min and 40 psig, respectively. The APPIfurnace temperature was set to 400° C. and the drying gas temperature to325° C. Ion source potentials was set as follows: Capillary: 3.0 kV,Capillary end cap (fragmentor) and skimmer are set to 150 V and 65 V,respectively. Mass spectra were recorded from 90-3000 amu for one minuteat a rate of 1 Hz and the resulting 60 spectra are co-added to improvethe signal to noise ratio.

The operator checked the signal shape at the beginning, middle and endof the mass range. An excessive sample load can be diagnosed by a signalcutoff through detector saturation. In case of signal cutoff, the signalwill rise and abruptly plateau before descending to the baseline. Whenthe operator observes such signal saturation, the sample should dilutethe sample until he obtains a good independent signal shape is obtained.

The spectra data is shown in FIG. 2A as the sample with an API gravityof 28.8°; and the data pertaining to spectrum is obtained and stored.Table 4A is an example of the full range of data. Table 4B is asimplified extraction from the raw data of Table 4A normalized from 0-1.The TOF-MS raw data was converted into cumulative mass fraction data,and data was stored as the analytic characterization data in step 325.The cumulative mass fraction data for API gravity of 28.8° is presentedin Tables 4A and 4B.

At step 330, an analytical value, the TOFMSI, was calculated as afunction of the weighted average of the masses (as stored in step 325)as determined by TOF-MS, that is, as a function of the cumulative massfraction, as in equation (5) above. The TOFMSI in the example using thedata in FIG. 2 , Table 4A and Table 4B is calculated as 539.0.

The TOFMSI, stored at step 335, was applied to step 390. At step 390,Equation (4) and the constants from Table 3 are applied for each of thelisted ADs, using the TOFMSI stored at step 335, the constants stored atstep 305, and the density of the oil sample stored at step 310, as shownbelow. Each of the determined ADs can be added to a virtual assay 395 ofthe oil sample. For example, this can be carried out as one step, or asplural steps, for instance, similar to steps 140, 150, 160, 170 and 180described herein in conjunction with FIG. 1 to calculate a plurality ofdifferent elemental composition values/physical properties/indicativeproperties that make up the virtual assay, for each of a total oilsample, a naphtha fraction, a gas oil fraction, a vacuum gas oilfraction and a vacuum residue fraction, respectively, and to produce thevirtual oil sample assay 195 at step 190.

Equation (4) is applied to each of the ADs that make up the virtualassay including those identified in Table 3, using the correspondingunits. In addition, the constants denoted in Table 3 are used as theconstants K_(AD), X1_(AD), X2_(AD), X3_(AD), X4_(AD), X5_(AD), X6_(AD)and X7_(AD)) in equation (4); the TOFMSI based on the data in FIG. 2A,Table 4A and Table 4B, calculated as 539.0 using equation (5) above, isused in equation (4); and the density p used in equation (4) for the ofthe oil sample under investigation is the 15° C./4° C. density in unitsof kilograms per liter using the method described in ASTM D4052, whichis 0.8828 Kg/L. The calculated AD values are provided for the oil sampleunder investigation in Table 5, compared to the actual values obtainedusing a conventional crude oil assay.

FIG. 4 shows an exemplary block diagram of a computer system 400 inwhich one embodiment of the present invention can be implemented.Computer system 400 includes a processor 420, such as a centralprocessing unit, an input/output interface 430 and support circuitry440. In certain embodiments, where the computer system 400 requires adirect human interface, a display 410 and an input device 450 such as akeyboard, mouse, pointer, motion sensor, microphone and/or camera arealso provided. The display 410, input device 450, processor 420, andsupport circuitry 440 are shown connected to a bus 490 which alsoconnects to a memory 460. Memory 460 includes program storage memory 470and data storage memory 480. Note that while computer system 400 isdepicted with direct human interface components display 410 and inputdevice 450, programming of modules and exportation of data canalternatively be accomplished over the input/output interface 430, forinstance, where the computer system 400 is connected to a network andthe programming and display operations occur on another associatedcomputer, or via a detachable input device as is known with respect tointerfacing programmable logic controllers.

Program storage memory 470 and data storage memory 480 can each comprisevolatile (RAM) and non-volatile (ROM) memory units and can also comprisehard disk and backup storage capacity, and both program storage memory470 and data storage memory 480 can be embodied in a single memorydevice or separated in plural memory devices. Program storage memory 470stores software program modules and associated data and stores one ormore of: a raw data receiving module 471, having one or more softwareprograms adapted to receive the analytic characterization data 125, forinstance obtained at step 120 in the process flow diagram of FIG. 1 ; ananalytical value calculation module 472, having one or more softwareprograms adapted to determine one or more analytical values 135 based onthe type of analytic characterization data 125 received by module 471,for instance calculated at step 130 in the process flow diagram of FIG.1 using equation (5) herein based on the TOF-MS data; one or moreassigned assay value calculation modules 473, having one or moresoftware programs adapted to determine a plurality of assigned assayvalues to produce a virtual assay 195 of an oil sample, for instanceusing the one or more analytical values 135 calculated by module 472 andthe set of constants 105 (and in certain embodiments the density 110),for instance as in step 190 in the process flow diagram of FIG. 1 (incertain embodiments using steps 140, 150, 160, 170 and 180 to calculateand assign a plurality of different elemental compositionvalues/physical properties/indicative properties that make up thevirtual assay, for each of a total oil sample, a naphtha fraction, a gasoil fraction, a vacuum gas oil fraction and a vacuum residue fraction,respectively, to produce corresponding assigned assay values for thevirtual assay 195, include including assigned assay values 145pertaining to the total oil sample, assigned assay values 155 pertainingto a naphtha fraction, assigned assay values 165 pertaining to a gas oilfraction, assigned assay values 175 pertaining to a vacuum gas oilfraction and assigned assay values 185 pertaining to a vacuum residuefraction); and optionally a density receiving module 474 (in embodimentsin which density is used to determine assigned assay values for thevirtual assay), shown in dashed lines, having one or more softwareprograms adapted to receive the density data 110, which in certainembodiments can be integrated in the raw data receiving module 471 orthe assigned assay value calculation modules 473 (shown by overlappingdashed lines). Data storage memory 480 stores results and other datagenerated by the one or more program modules of the present invention,including the constants 105, the density 110, the analyticcharacterization data 125, the one or more analytical values 135, andthe assigned assay values (which can be a single set of assigned datavalues to produce the virtual assay 195, or alternatively delineated bytype including the assigned assay values 145, 155, 165, 175 and 185described herein).

It is to be appreciated that the computer system 400 can be any computersuch as a personal computer, minicomputer, workstation, mainframe, adedicated controller such as a programmable logic controller, or acombination thereof. While the computer system 400 is shown, forillustration purposes, as a single computer unit, the system cancomprise a group of computers which can be scaled depending on theprocessing load and database size.

Computer system 400 generally supports an operating system, for examplestored in program storage memory 470 and executed by the processor 420from volatile memory. According to an embodiment of the invention, theoperating system contains instructions for interfacing computer system400 to the Internet and/or to private networks.

Note that steps 110 and 120 can be carried out separate from or withinthe computer system 400. For example, step 110 can be carried out andthe data entered into the computer system 400, for example via datastorage memory 480, or as a single value incorporated in the programstorage memory 470 for one or more of the modules. Step 120 can becarried out and the analytic characterization data entered into thecomputer system 400, for example via data storage memory 480,represented as the analytic characterization data 125.

In alternate embodiments, the present invention can be implemented as acomputer program product for use with a computerized computing system.Those skilled in the art will readily appreciate that programs definingthe functions of the present invention can be written in any appropriateprogramming language and delivered to a computer in any form, includingbut not limited to: (a) information permanently stored on non-writeablestorage media (e.g., read-only memory devices such as ROMs or CD-ROMdisks); (b) information alterably stored on writeable storage media(e.g., floppy disks and hard drives); and/or (c) information conveyed toa computer through communication media, such as a local area network, atelephone network, or a public network such as the Internet. Whencarrying computer readable instructions that implement the presentinvention methods, such computer readable media represent alternateembodiments of the present invention.

As generally illustrated herein, the system embodiments can incorporatea variety of computer readable media that comprise a computer usablemedium having computer readable code means embodied therein. One skilledin the art will recognize that the software associated with the variousprocesses described can be embodied in a wide variety of computeraccessible media from which the software is loaded and activated.Pursuant to In re Beauregard, 35 U.S.P.Q.2d 1383 (U.S. Pat. No.5,710,578), the present invention contemplates and includes this type ofcomputer readable media within the scope of the invention. In certainembodiments, pursuant to In re Nuijten, 500 F.3d 1346 (Fed. Cir. 2007)(U.S. patent application Ser. No. 09/211,928), the scope of the presentclaims is limited to computer readable media, wherein the media is bothtangible and non-transitory.

It is to be understood that like numerals in the drawings represent likeelements through the several figures, and that not all components and/orsteps described and illustrated with reference to the figures arerequired for all embodiments or arrangements. Further, the terminologyused herein is for the purpose of describing particular embodiments onlyand is not intended to be limiting of the invention. As used herein, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willbe further understood that the terms “including,” “comprising,” or“having,” “containing,” “involving,” and variations thereof herein, whenused in this specification, specify the presence of stated features,integers, steps, operations, elements, and/or components, but do notpreclude the presence or addition of one or more other features,integers, steps, operations, elements, components, and/or groupsthereof.

It should be noted that use of ordinal terms such as “first,” “second,”“third,” etc., in the claims to modify a claim element does not byitself connote any priority, precedence, or order of one claim elementover another or the temporal order in which acts of a method areperformed, but are used merely as labels to distinguish one claimelement having a certain name from another element having a same name(but for use of the ordinal term) to distinguish the claim elements.

Notably, the figures and examples above are not meant to limit the scopeof the present disclosure to a single implementation, as otherimplementations are possible by way of interchange of some or all thedescribed or illustrated elements. Moreover, where certain elements ofthe present disclosure can be partially or fully implemented using knowncomponents, only those portions of such known components that arenecessary for an understanding of the present disclosure are described,and detailed descriptions of other portions of such known components areomitted so as not to obscure the disclosure. In the presentspecification, an implementation showing a singular component should notnecessarily be limited to other implementations including a plurality ofthe same component, and vice-versa, unless explicitly stated otherwiseherein. Moreover, applicants do not intend for any term in thespecification or claims to be ascribed an uncommon or special meaningunless explicitly set forth as such. Further, the present disclosureencompasses present and future known equivalents to the known componentsreferred to herein by way of illustration.

The foregoing description of the specific implementations will so fullyreveal the general nature of the disclosure that others can, by applyingknowledge within the skill of the relevant art(s), readily modify and/oradapt for various applications such specific implementations, withoutundue experimentation, without departing from the general concept of thepresent disclosure. Such adaptations and modifications are thereforeintended to be within the meaning and range of equivalents of thedisclosed implementations, based on the teaching and guidance presentedherein. It is to be understood that the phraseology or terminologyherein is for the purpose of description and not of limitation, suchthat the terminology or phraseology of the present specification is tobe interpreted by the skilled artisan in light of the teachings andguidance presented herein, in combination with the knowledge of oneskilled in the relevant art(s). It is to be understood that dimensionsdiscussed or shown are drawings are shown accordingly to one example andother dimensions can be used without departing from the disclosure.

The subject matter described above is provided by way of illustrationonly and should not be construed as limiting. Various modifications andchanges can be made to the subject matter described herein withoutfollowing the example embodiments and applications illustrated anddescribed, and without departing from the true spirit and scope of theinvention encompassed by the present disclosure, which is defined by theset of recitations in the following claims and by structures andfunctions or steps which are equivalent to these recitations.

TABLE 1 Fraction Boiling Point, ° C. Methane −161.5  Ethane −88.6Propane −42.1 Butanes  −6.0 Light Naphtha 36-90 Mid Naphtha  90-160Heavy Naphtha 160-205 Light gas Oil 205-260 Mid Gas Oil 260-315 Heavygas Oil 315-370 Light Vacuum Gas Oil 370-430 Mid Vacuum Gas Oil 430-480Heavy vacuum gas oil 480-565 Vacuum Residue 565+

TABLE 2 Property Unit Property Type Fraction Yield W % or V % Yield AllAPI Gravity ° Physical All Kinematic Viscosity @ 38° C. cSt PhysicalFraction boiling >250° C. Refractive Index @ 20° C. Unitless PhysicalFraction boiling <400° C. Sulfur W % or ppmw Composition All MercaptanSulfur W % Composition Fraction boiling <250° C. Nickel Ppmw CompositionFraction boiling >400° C. Nickel Ppmw Composition Fraction boiling >400°C. Nitrogen Ppmw Composition All Flash Point ° C. Indicative All CloudPoint ° C. Indicative Fraction boiling >250° C. Pour Point ° C.Indicative Fraction boiling >250° C. Freezing Point ° C. IndicativeFraction boiling >250° C. Micro Carbon Residue W % Indicative Fractionboiling >300° C. Smoke Point Mm Indicative Fraction boiling between150-250° C. Octane Number Unitless Indicative Fraction boiling <250° C.Cetane Index Unitless Indicative Fraction boiling between 150-400° C.Aniline Point ° C. Indicative Fraction boiling <520° C.

TABLE 3 Fraction property Units K_(AD) X1_(AD) Naphtha Aromatics (Aro) W% 2.980414E+05 −1.026580E+06 Hydrogen (H) W % 1.007998E+04 −3.539106E+04Paraffins (P) W % 1.451427E+06 −5.039909E+06 Sulfur (S) ppmw−6.105903E+05   0.000000E+00 Octane Number (ON) Unitless 6.057876E+04−2.124626E+05 Gas Oil (GO) Aniline Point (AP) ° C. 2.894881E+05−9.918801E+05 Cetane Number (CN) Unitless 4.569187E+05 −1.560562E+06Cloud Point (CP) ° C. 8.428790E+03 −2.613190E+04 Nitrogen (N) ppmw1.782214E+06 −6.050647E+06 Sulfur (S) ppmw 2.363332E+08 −8.106348E+08Kinematic Viscosity @40° C. cSt −2.935903E+04   1.010524E+05 Pour Point(PP) ° C. −1.169451E+05   4.096141E+05 Vacuum Gas Oil Nitrogen (N) ppmw6.646728E+05  0.000000E+00 (VGO) Sulfur (S) ppmw 7.610649E+06 0.000000E+00 Vacuum Residue Micro Carbon Residue (MCR) W % 4.948877E+04 0.000000E+00 (VR) Sulfur (S) ppmw 4.596183E+07  0.000000E+00 Oil SampleC5-Asphaltenes (C5A) W % 5.381377E+04 −1.856455E+05 Micro Carbon Resid(MCR) W % 2.605001E+05 −8.950071E+05 Pour Point (PP) ° C. −1.305386E+06  4.488002E+06 Kinematic Viscosity @100° C. cSt −2.545607E+04  9.031536E+04 Kinematic Viscosity @70° C. cSt −2.989314E+05  1.044536E+06 Nitrogen (N) ppmw −3.460267E+06   1.108482E+07 Sulfur (S)ppmw 9.663380E+08 −3.322084E+09 Total Acid Number (TAN) mg KOH/100 g5.718560E+03 −1.964193E+04 Aromatics (Aro) W % −9.722961E+04  3.475980E+05 Fraction property Units X2_(AD) X3_(AD) Naphtha Aromatics(Aro) W % 1.185677E+06 −4.564133E+05 Hydrogen (H) W % 3.933237E+04−1.448098E+04 Paraffins (P) W % 5.767850E+06 −2.198306E+06 Sulfur (S)ppmw −9.717499E+04   0.000000E+00 Octane Number (ON) Unitless2.487175E+05 −9.725206E+04 Gas Oil (GO) Aniline Point (AP) ° C.1.110081E+06 −4.115490E+05 Cetane Number (CN) Unitless 1.749055E+06−6.499532E+05 Cloud Point (CP) ° C. 3.417509E+04 −1.504746E+04 Nitrogen(N) ppmw 6.697322E+06 −2.439738E+06 Sulfur (S) ppmw 9.102584E+08−3.390435E+08 Kinematic Viscosity @40° C. cSt −1.131976E+05  4.201161E+04 Pour Point (PP) ° C. −4.516228E+05   1.632271E+05 VacuumGas Oil Nitrogen (N) ppmw 1.637468E+05  0.000000E+00 (VGO) Sulfur (S)ppmw 2.827587E+05  0.000000E+00 Vacuum Residue Micro Carbon Residue(MCR) W % 9.424309E+03  0.000000E+00 (VR) Sulfur (S) ppmw 5.490178E+06 0.000000E+00 Oil Sample C5-Asphaltenes (C5A) W % 2.081417E+05−7.729373E+04 Micro Carbon Resid (MCR) W % 1.002047E+06 −3.713700E+05Pour Point (PP) ° C. −5.028087E+06   1.862906E+06 Kinematic Viscosity@100° C. cSt −1.294260E+05   6.067156E+04 Kinematic Viscosity @70° C.cSt −1.257706E+06   5.066089E+05 Nitrogen (N) ppmw −1.355087E+07  5.584982E+06 Sulfur (S) ppmw 3.721533E+09 −1.380412E+09 Total AcidNumber (TAN) mg KOH/100 g 2.161346E+04 −7.798589E+03 Aromatics (Aro) W %−3.883711E+05   1.443728E+05 Fraction property Units X4_(AD) X5_(AD)Naphtha Aromatics (Aro) W % −1.167423E+01   2.399766E−02 Hydrogen (H) W% 3.388769E+00 −6.408573E−03 Paraffins (P) W % 1.023121E+02−1.989024E−01 Sulfur (S) ppmw 3.869187E+03 −8.206237E+00 Octane Number(ON) Unitless 2.182939E−01 −2.994297E−03 Gas Oil (GO) Aniline Point (AP)° C. 3.639903E+01 −5.491284E−02 Cetane Number (CN) Unitless 4.227558E+01−5.783636E−02 Cloud Point (CP) ° C. −1.221468E+01   2.307521E−02Nitrogen (N) ppmw 2.296875E+02 −2.336764E−01 Sulfur (S) ppmw2.486134E+04 −3.687021E+01 Kinematic Viscosity @40° C. cSt−4.343672E+00   7.060609E−03 Pour Point (PP) ° C. −4.350263E+01  7.282422E−02 Vacuum Gas Oil Nitrogen (N) ppmw −4.397803E+03  9.986972E+00 (VGO) Sulfur (S) ppmw −4.960720E+04   1.069321E+02 VacuumResidue Micro Carbon Residue (MCR) W % −3.245085E+02   7.270210E−01 (VR)Sulfur (S) ppmw −3.003131E+05   6.595234E+02 Oil Sample C5-Asphaltenes(C5A) W % 8.507174E+00 −1.406425E−02 Micro Carbon Resid (MCR) W %3.625144E+01 −5.546420E−02 Pour Point (PP) ° C. −1.827392E+02  2.679504E−01 Kinematic Viscosity @100° C. cSt 3.609633E+01−6.472088E−02 Kinematic Viscosity @70° C. cSt 6.600222E+01 −1.129278E−01Nitrogen (N) ppmw 2.904143E+03 −5.305696E+00 Sulfur (S) ppmw1.338146E+05 −2.032547E+02 Total Acid Number (TAN) mg KOH/100 g1.433190E+00 −2.141004E−03 Aromatics (Aro) W % −4.106734E+01  8.589613E−02 Fraction property Units X6_(AD) X7_(AD) Naphtha Aromatics(Aro) W % −1.676996E−05   3.137941E−01 Hydrogen (H) W % 4.440164E−06−3.613393E−01 Paraffins (P) W % 1.376552E−04 −7.743619E+00 Sulfur (S)ppmw 5.394193E−03  2.947244E+02 Octane Number (ON) Unitless 2.459641E−06 1.002735E+00 Gas Oil (GO) Aniline Point (AP) ° C. 3.775622E−05−1.124112E+01 Cetane Number (CN) Unitless 3.777913E−05 −1.479324E+01Cloud Point (CP) ° C. −1.644323E−05   1.682674E+00 Nitrogen (N) ppmw1.543644E−04 −1.297137E+02 Sulfur (S) ppmw 2.380760E−02 −6.828496E+03Kinematic Viscosity @40° C. cSt −4.915355E−06   1.107860E+00 Pour Point(PP) ° C. −5.269819E−05   1.161508E+01 Vacuum Gas Oil Nitrogen (N) ppmw−6.789298E−03  −5.458464E+02 (VGO) Sulfur (S) ppmw −7.507425E−02 −7.910201E+02 Vacuum Residue Micro Carbon Residue (MCR) W %−4.969913E−04  −3.218373E+01 (VR) Sulfur (S) ppmw −4.560012E−01 −1.794201E+04 Oil Sample C5-Asphaltenes (C5A) W % 9.858428E−06−2.103867E+00 Micro Carbon Resid (MCR) W % 3.846036E−05 −1.105073E+01Pour Point (PP) ° C. −1.874253E−04   6.357069E+01 Kinematic Viscosity@100° C. cSt 4.511961E−05 −5.993973E+00 Kinematic Viscosity @70° C. cSt7.877355E−05 −1.393141E+01 Nitrogen (N) ppmw 3.720955E−03 −4.466862E+02Sulfur (S) ppmw 1.389319E−01 −3.994603E+04 Total Acid Number (TAN) mgKOH/100 g 1.563717E−06 −5.302837E−01 Aromatics (Aro) W % −6.079852E−05  8.931577E−01

TABLE 4A Fraction of m/z Cumulative cumulative (amu) Abundance Abundanceabundances 222.1269 12523.11 12523.11 0.001832 222.2197 2048.44 14571.550.002131 223.1301 7259.21 21830.76 0.003193 223.2239 926.18 22756.940.003328 224.1421 15536.37 38293.31 0.005601 225.1356 6244.04 44537.350.006514 225.2056 1539.16 46076.51 0.006739 226.0705 29112.23 75188.740.010997 226.1581 11768.91 86957.65 0.012718 1233.056 368.56 68339590.999533 1234.065 345.28 6834305 0.999583 1235.06 352.75 68346580.999635 1237.068 371.8 6835029 0.999689 1238.052 350.76 68353800.999741 1239.062 360.04 6835740 0.999793 1243.074 356.24 68360960.999845 1245.089 356.17 6836453 0.999897 1249.087 349.99 68368030.999949 1253.082 351.33 6837154 1

TABLE 4B Cumulative Mass Fraction Mass (amu) 0.00 213 0.05 239 0.10 2590.20 287 0.30 317 0.40 357 0.50 396 0.60 442 0.70 498 0.80 570 0.90 6810.95 790 1.00 1209

TABLE 5 Conventional Calculated Crude Oil AD Value AD Description UnitAssay Value (Equation (4) Naphtha, Aro W % 11.0 11.0 Naphtha, H W % 15.014.7 Naphtha, P W % 76.0 76.1 Naphtha, S ppmw 876 876 Naphtha, ONUnitless 52.0 52.4 GO, AP ° C. 66.0 66.1 GO, CN Unitless 60.0 59.2 GO,CP ° C. −10.0 −10.4 GO, N ppmw 71.0 79.2 GO, S ppmw 13,090 14,454 GO,Kinematic cSt 3.0 2.9 Viscosity @40° C. GO, PP ° C. −9.0 −9.3 VGO, Nppmw 617 617 VGO, S ppmw 28,800 28,800 VR, MCR W % 12.0 12.4 VR, S ppmw52,700 52,700 Oil Sample, C5A W % 1.0 1.4 Oil Sample, MCR W % 6.0 6.1Oil Sample, PP ° C. −15.0 −16.6 Oil Sample, Kinematic cSt 12.0 11.7Viscosity @100° C. Oil Sample, Kinematic cSt 22.0 21.6 Viscosity @70° C.Oil Sample, N ppmw 829 765 Oil Sample, S ppmw 30,000 30,764 Oil Sample,TAN mg KOH/100 g 0.0 0.1 Oil Sample, Aro W % 20.0 21.2

1. A method for producing a virtual assay of an oil sample, wherein theoil sample is characterized by a density, selected from the groupconsisting of crude oil, bitumen and shale oil, and characterized bynaphtha, gas oil, vacuum gas oil and vacuum residue fractions, themethod comprising: entering into a computer time of flight massspectroscopy (TOF-MS) data indicative of cumulative mass fraction datafor a solution of the oil sample without distillation in a TOF-MSsolvent; calculating and assigning, as a function of the TOF-MS data, ananalytical value (AV); and calculating and assigning, as a function ofthe AV and the density of the oil sample, virtual assay data of the oilsample and the naphtha, gas oil, vacuum gas oil and vacuum residuefractions, said virtual assay data comprising a plurality of assigneddata values.
 2. The method of claim 1, wherein virtual assay datacomprises: a plurality of assigned assay data values pertaining to theoil sample including one or more of aromatic content, C5-asphaltenescontent, elemental compositions of sulfur and nitrogen, micro-carbonresidue content, total acid number and viscosity; a plurality ofassigned assay values pertaining to the vacuum residue fraction of theoil sample including one or more of elemental composition of sulfur andmicro-carbon residue content; a plurality of assigned assay valuespertaining to the vacuum gas oil fraction of the oil sample includingelemental compositions of one or more of sulfur and nitrogen; aplurality of assigned assay values pertaining to the gas oil fraction ofthe oil sample including one or more of elemental compositions of sulfurand nitrogen, viscosity, and indicative properties including anilinepoint, cetane number, cloud point and pour point; and a plurality ofassigned assay values pertaining to the naphtha fraction of the oilsample including one or more of aromatic content, elemental compositionof hydrogen and sulfur, paraffin content and octane number.
 3. Themethod of claim 1, wherein virtual assay data comprises: a plurality ofassigned assay data values pertaining to the oil sample includingaromatic content, C5-asphaltenes content, elemental compositions ofsulfur and nitrogen, micro-carbon residue content, total acid number andviscosity; a plurality of assigned assay values pertaining to the vacuumresidue fraction of the oil sample including elemental composition ofsulfur and micro-carbon residue content; a plurality of assigned assayvalues pertaining to the vacuum gas oil fraction of the oil sampleincluding elemental compositions of sulfur and nitrogen; a plurality ofassigned assay values pertaining to the gas oil fraction of the oilsample including elemental compositions of sulfur and nitrogen,viscosity, and indicative properties including aniline point, cetanenumber, cloud point and pour point; and a plurality of assigned assayvalues pertaining to the naphtha fraction of the oil sample includingaromatic content, elemental composition of hydrogen and sulfur, paraffincontent and octane number.
 4. The method of claim 3, wherein virtualassay data further comprises: yields of fractions from the oil sample asmass fractions of boiling point ranges, including one or more ofnaphtha, gas oil, vacuum gas oil and vacuum residue; compositioninformation of hydrogen sulfide and/or mercaptans in the oil sampleand/or its fractions; elemental compositions of one or more of carbon,hydrogen, nickel, and vanadium; physical properties of the oil sampleand/or its fractions including one or more of API gravity and refractiveindex; or indicative properties of the oil sample and/or its fractionsincluding one or more of flash point, freezing point and smoke point. 5.The method of claim 1, further comprising operating a time of flightmass spectrometer to obtain the TOF-MS data over a range ofmass-to-charge ratios, by analyzing the solution of the oil samplewithout distillation in the TOF-MS mass spectroscopy solvent.
 6. Themethod of claim 1, wherein each assay value is determined by amulti-variable polynomial equation with predetermined constantcoefficients developed using linear regression techniques, whereincorresponding variables are the AV and the density of the oil sample. 7.The method of claim 6, wherein each assay value is determined byAD=K _(AD) +X1_(AD) *AV+X2_(AD) *AV ² +X3_(AD) *AV ³ +X4_(AD) *ρ*AVwhere: AD is the assigned assay value that is a value and/or propertyrepresentative of an elemental composition value, a physical property oran indicative property; AV is the analytical value of the oil sample; ρis the density of the oil sample; and K_(AD), X1_(AD), X2_(AD), X3_(AD),and X4_(AD) are constants.
 8. The method of claim 6, wherein each assayvalue is determined byAD=K _(AD) +X1_(AD) *ρ+X2_(AD)*ρ² +X3_(AD)*ρ³ +X4_(AD) *AV+X5_(AD) *AV ²+X6_(AD) *AV ³ +X7_(AD) *ρ*AV where: AD is the assigned assay value thatis a value and/or property representative of an elemental compositionvalue, a physical property or an indicative property; AV is theanalytical value of the oil sample; ρ is the density of the oil sample;and K_(AD), X1_(AD), X2_(AD), X3_(AD), X4_(AD), X5_(AD), X6_(AD) andX7_(AD) are constants.
 9. The method of claim 8, wherein the analyticalvalue is an index derived from a weighted average of masses derived fromthe TOF-MS data.
 10. The method of claim 9, wherein the index isobtained by a function:$({TOFMSI}) = \frac{\left\lbrack {{\sum}_{x,{y = 5},10,20,30,40,50,60,70,80,90,95}M_{x}*W_{y}} \right\rbrack}{\left\lbrack {{\sum}_{{y = 5},10,20,30,40,50,60,70,80,90,95}W_{y}} \right\rbrack}$where: TOFMSI is the index; M=mass, over a range of x percentage from 0to 100; and W=weight fraction of the mass, i.e., cumulative massfraction over a range y.
 11. A system for producing a virtual assay ofan oil sample, wherein the oil sample is characterized by a density,selected from the group consisting of crude oil, bitumen and shale oil,and characterized by naphtha, gas oil, vacuum gas oil and vacuum residuefractions, the system comprising: a time of flight mass spectrometerthat outputs time of flight mass spectroscopy (TOF-MS) data; anon-volatile memory device that stores calculation modules and data, thedata including the TOF-MS data, wherein the TOF-MS data is indicative ofcumulative mass fraction data for a solution of the oil sample withoutdistillation in a TOF-MS solvent; a processor coupled to thenon-volatile memory device; a first calculation module that is stored inthe non-volatile memory device and that is executed by the processor,wherein the first calculation module calculates an analytical value (AV)as a function of the TOF-MS data; and a second calculation module thatis stored in the non-volatile memory device and that is executed by theprocessor, wherein the second calculation module calculates, as afunction of the AV and the density of the oil sample, virtual assay dataof the oil sample and the naphtha, gas oil, vacuum gas oil and vacuumresidue fractions, said virtual assay data comprising a plurality ofassigned data values.
 12. The system as in claim 11, wherein virtualassay data comprises: a plurality of assigned assay data valuespertaining to the oil sample including aromatic content, C5-asphaltenescontent, elemental compositions of sulfur and nitrogen, micro-carbonresidue content, total acid number and viscosity; a plurality ofassigned assay values pertaining to the vacuum residue fraction of theoil sample including elemental composition of sulfur and micro-carbonresidue content; a plurality of assigned assay values pertaining to thevacuum gas oil fraction of the oil sample including elementalcompositions of sulfur and nitrogen; a plurality of assigned assayvalues pertaining to the gas oil fraction of the oil sample includingelemental compositions of sulfur and nitrogen, viscosity, and indicativeproperties including aniline point, cetane number, cloud point and pourpoint; a plurality of assigned assay values pertaining to the naphthafraction of the oil sample including aromatic content, elementalcomposition of hydrogen and sulfur, paraffin content and octane number.13. The system as in claim 12, wherein virtual assay data furthercomprises: yields of fractions from the oil sample as mass fractions ofboiling point ranges, including one or more of naphtha, gas oil, vacuumgas oil and vacuum residue; composition information of hydrogen sulfideand/or mercaptans in the oil sample and/or its fractions; elementalcompositions of one or more of carbon, hydrogen, nickel, and vanadium;physical properties of the oil sample and/or its fractions including oneor more of API gravity and refractive index; or indicative properties ofthe oil sample and/or its fractions including one or more of flashpoint, freezing point and smoke point.
 14. The system of claim 11,wherein each assay value is calculated and assigned by the secondcalculation module with a multi-variable polynomial equation withpredetermined constant coefficients developed using linear regressiontechniques, wherein corresponding variables are the AV and the densityof the oil sample.
 15. The system of claim 14, wherein each assay valueis calculated and assigned by the second calculation module with afunction:AD=K _(AD) +X1_(AD) *AV+X2_(AD) *AV ² +X3_(AD) *AV ³ +X4_(AD) *ρ*AVwhere: AD is the assigned assay value that is a value and/or propertyrepresentative of an elemental composition value, a physical property oran indicative property; AV is the analytical value of the oil sample; ρis the density of the oil sample; and K_(AD), X1_(AD), X2_(AD), X3_(AD),and X4_(AD) are constants.
 16. The system of claim 14, wherein eachassay value is calculated and assigned by the second calculation modulewith a function:AD=K _(AD) +X1_(AD) *ρ+X2_(AD)*ρ² +X3_(AD)*ρ³ +X4_(AD) *AV+X5_(AD) *AV ²+X6_(AD) *AV ³ +X7_(AD) *ρ*AV where: AD is the assigned assay value thatis a value and/or property representative of an elemental compositionvalue, a physical property or an indicative property; AV is theanalytical value of the oil sample; ρ is the density of the oil sample;and K_(AD), X1_(AD), X2_(AD), X3_(AD), X4_(AD), X5_(AD), X6_(AD) andX7_(AD) are constants.
 17. The system of claim 16, wherein theanalytical value is an index derived from a weighted average of massesderived from the TOF-MS data.
 18. The system of claim 17, wherein theindex is obtained by a function:$({TOFMSI}) = \frac{\left\lbrack {{\sum}_{x,{y = 5},10,20,30,40,50,60,70,80,90,95}M_{x}*W_{y}} \right\rbrack}{\left\lbrack {{\sum}_{{y = 5},10,20,30,40,50,60,70,80,90,95}W_{y}} \right\rbrack}$where: TOFMSI is the index; M=mass, over a range of x percentage from 0to 100; and W=weight fraction of the mass, i.e., cumulative massfraction over a range y.